QUIC - disable QUIC under recent pathological connection errors.

chrome/browser/resources/net_internals/quic_view.html

 <div id=quic-view-tab-content class=content-box>
   <ul style='margin-top:0'>
     <li>QUIC Enabled: <span jscontent="!!quic_enabled"></span></li>
     <!-- "alternative_service_probability_threshold" is used since release 44,
     see https://crrev.com/1091283007.
     "alternate_protocol_probability_threshold" is here to support importing
     netlog json files from earlier browsers.
     TODO(bnc): Deprecate around 2016 January. --!>
     <li>Alternative Service Probability Threshold: <span jscontent="$this.alternative_service_probability_threshold || $this.alternate_protocol_probability_threshold"></span></li>
     <li>Origin To Force QUIC On: <span jscontent="origin_to_force_quic_on"></span></li>
     <li>QUIC connection options: <span jscontent="connection_options"></span></li>
     <li>Consistent Port Selection Enabled: <span jscontent="!!enable_quic_port_selection"></span></li>
+    <li jsdisplay="$this.disabled_reason && disabled_reason.length > 0">QUIC dynamically disabled: <span jscontent="disabled_reason"></span></li>
   </ul>
 
   <h4>QUIC sessions</h4>
     <!-- Only one of these two are shown -->
     <div jsdisplay="!($this.sessions && sessions.length > 0)">None</div>
     <div jsdisplay="$this.sessions && sessions.length > 0">
       <a href="#events&q=type:QUIC_SESSION%20is:active">View live QUIC sessions</a>
       <p>
         <table class="styled-table">
           <thead>
@@ skipping 25 matching lines @@
               <td jscontent="packets_sent"></td>
               <td jscontent="packets_lost"></td>
               <td jscontent="packets_received"></td>
               <td jscontent="connected"></td>
             </tr>
           </tbody>
         </table>
       </p>
     </div>
 </div>